It’s hard when you can’t control it. I understand the feeling. Just wanted to put in my 2 cents and maybe it would help you or anyone else reading this- If I have to speak and I feel like I’m going to stutter or if it’s a word that I normally have a hard time with - I quietly make a hard “h” sound like saying the word “heavy” without the ‘eavy’ part. I just started doing that one day and it’s greatly helped me. Sometimes I fuck it up but if you quietly say it and exhale continue your sentence, people can’t tell. I hope this helps you like it helped me!